A great deal of effort has been directed to the location of wireless devices, most notably in support of the Federal Communications Commission's (FCC) rules for Enhanced 911 (E911). The E911 rules seek to improve the effectiveness and reliability of 911 service by providing 911 dispatchers with additional information on location of 911 calls. The implementation of E911 requires wireless carriers to provide precise location information, within 50 to 300 meters in most cases. For example, network-based systems are required to meet a precision within a range of 300 meters for about 95% of callers.
Hence, networks must design a framework for precisely but reliably locate a user end device without requiring the user end device to perform complex computations.